The present invention relates in general to devices for cooling and warming, and more particularly, for effecting body temperature changes in humans who wear or apply such a device to the body.
It is well known that humans who are engaged in strenuous activity, such as sports, may undergo a detrimental body temperature increase, and associated fatigue and decreased performance. Similarly, it is also well known that in cold climates, human body temperature may decrease as a result of environmental exposure, also resulting in fatigue and the potential for serious injury. Depending on atmospheric and environmental conditions, a normal human heat transfer function may be assisted, under these and other environmental conditions, by directly applying warm or cold substances to the body in order to effect a local temperature differential, and thus, heat transfer.
In addition, it is well known that direct application of heat or cold to various injuries, especially stress injuries to muscles, joints, and tendons, may provide a therapeutic effect.
For example, athletes engaged in sporting activities often apply ice packs during periods of rest in order to cool themselves and regain strength for continued activity. In addition, a common therapy for stress injuries to a limb or joint often includes a first application of ice packs directly to the injured limb or joint, as well as a later application of heat via electric heating pad.
There are several known prior art devices for effecting cooling or warming the human body. For example, U.S. Pat. No. 5,766,235 to Kostopoulos discloses a shallow, insulative pouch containing a removable cooling pack for keeping the inside of a user""s wrists cool during physical activity. Similarly, U.S. Pat. No. 5,514,170 discloses a cold pack device for extending around a body part in a self-supporting manner, the cold pack including an insulative housing to retain a cold pack, and straps for securing the cold pack to a user""s head or upper arms.
The thermal efficiency of these prior art devices varies widely. Under circumstances in which a plentiful supply of hot or cold substances exist, or where an external power supply is nearby, thermal efficiency may not be a concern. However, under circumstances in which the supply of hot or cold substances is limited or where there is no nearby power source, e.g., during activities such as hiking, biking, or running, thermal efficiency of such a warming or cooling device is a principal concern. In these activities, highly efficient warming or cooling devices are required in order to provide relatively long duration heat transfer.
Another important consideration in the implementation of warming or cooling devices is how easily and securely the device may be worn while engaged in strenuous activity. Bulky or protruding devices restrict movement of the wearer and may add unnecessary weight, thus detrimentally affecting human performance and increasing the likelihood that such devices will not be worn long enough to achieve the desired result.
Like other sporting or therapeutic devices, ease of operation, rapid recharging, and durability are also factors that influence the effectiveness of warming or cooling devices. Warming or cooling devices intended for use by persons, whether during strenuous activity or while at rest, should thus be easy to operate, simple to recharge with a fresh warming or cooling source, and be durable and secure so as to withstand rapid movements and enable prolonged and repeated use.
Body temperature changes are effected by the apparatus of the present invention through the use of a shell containing an easily replaced thermal insert. The thermal insert contains a high thermal capacity substance. The shell containing the thermal insert may be strapped or otherwise secured in place on the body, preferably on the forearms, directly over the wrists. A temperature gradient between the warmed or chilled thermal insert causes desirable heat transfer between the body and thermal insert.
Efficiency of the band is improved by locating a layer of thermal insulation, a radiant barrier, or an insulating air space between the high thermal capacity substance and the environment.
Effectiveness of the band is greatly improved by locating the band in a preferred position directly over the wrists, where heat transfer is effected between the thermal insert and the tissue underlying the wearer""s forearm, including the wearer""s radial arteries and nearby blood veins. Thus, the band of the present invention not only causes a local temperature change of the tissue underlying the wearer""s forearm, but also desirably causes a global, body core temperature change. This dual temperature change caused by the band of the present invention, as used in the preferred position thereby facilitates reducing heat-related fatigue and improving long-term performance.
Ergonomics and ease of use of the band of the present invention is improved by incorporating elastic and absorbent cuffs, as well as by employing a concave bottom surface and a rounded end portion of the shell (either of which aiding use of the band in the preferred position as discussed herein).
The foregoing has outlined the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention.